[Taxacom] Jurassic primates???
John Grehan
calabar.john at gmail.com
Wed Jun 13 21:29:40 CDT 2018
Not to prejudge what Heads might say on this, but Ken points to a really
interesting anomaly and one that should receive attention rather than being
suppressed (as proposed by various biogeographic ‘authorities’). The
anomaly is what Ken says – that there is a difference between the
biogeographic prediction and the oldest fossils. The scientific interest
here lies not in that there is a difference (after all there are many cases
where molecular divergences predate the oldest fossils of taxa), but how
does one empirically judge whether the difference it too large to be
seriously considered. I think this is a very credible question and not one
that I have seen (that I can recall) being properly discussed by skeptics
for origins older than fossils. It’s clearly an interesting problem. How
much older becomes incredible? How many millions of years? So for primates
an age that is triple the ‘generally accepted age’ is seen to be
problematic. What if it were just double? What if it were a bit less than
that? The problem here is that there seems to be no objective criterion and
so it comes down to personal judgment that itself carries no scientific
merit.
So for me I have seen the biogeographic patterns and tectonic correlations
which point to an age substantially older than the oldest fossils. It could
be that all these biogeographic matches are pure coincidence and actually
mean nothing (just like Creationists want to believe that God made it look
like evolution occurred when in fact it did not). That is an alternative,
but not one that I have yet seen argued other than by personal belief.
There is the case of angiosperms that are the sister taxa to some
gymnosperms which means that they have a shared evolutionary age, but this
goes back much further in the gymnosperms – Triassic vs early Cretaceous
for angiosperms (assuming that is still the case). So what to do?Definitely
an interesting question for evolutionary biology. It would be interesting
for an editor of a major journal to invite the different viewpoints to lay
out their evidence and interpretations as I am sure many would find that
interesting to read.
I don’t mind if anyone calls the much older origins fairy tales or not (and
panbiogeography has been characterized in much worse ways anyway). More
interested in how the evidence is argued. I call dispersal narratives fairy
tales because they are not empirically grounded (not generated from
evidence), but rather just invoked or imagined. It’s the same for selection
stories to ‘explain’ the origin of ‘adaptations’. At least the
panbiogeographic stories (all scientific explanations are stories) are
generated from an interpretation of evidence indicating a historical
relationship between geological and biological events.
What’s the point of asking if anyone agrees with panbiogeographic
perspectives on primates? Does belief determine reality the way it did for
Baldwin and Chamberlain? And we all know what happened to that.
Cheers, John Grehan
On Wed, Jun 13, 2018 at 9:50 PM, Kenneth Kinman <kinman at hotmail.com> wrote:
> Michael,
>
> Your 2010 paper proposes that Old World monkeys and New World
> monkeys split about 130 million years ago. That age more than doubles what
> most mammalogists would accept as likely. And your estimate of about 185
> million years ago for the origin of Primates is roughly triple the
> generally accepted age.
>
> And fossil primates can be identified by mere scraps of different
> parts of their skeleton, and the morphology of their various teeth have
> been intensely studied. But I guess you really believe that there were
> Jurassic and Early Cretaceous primates and that somehow noone has ever
> found even a scrap of their skeletons in the fossil record between 185 and
> 65 million years ago.
>
> Extraordinary claims require extraordinary evidence, and Goswami
> and Upchurch provide many reasons for doubting your extraordinary claims.
> They didn't call your hypothesis a "fairy tale", but I suspect they
> probably would have liked to do so. They were just too polite.
>
> I would be interested to know if anyone subscribed to Taxacom
> (besides Michael Heads and John Grehan) find the hypothesis in Heads 2010
> paper at all convincing.
>
>
> Heads, 2010: https://onlinelibrary.wiley.com/doi/abs/10.1111/j.1463-
> 6409.2009.00411.x
>
>
> Reply by Goswami and Upchurch, 2010: https://www.researchgate.net/
> publication/229977172_The_dating_game_A_reply_to_Heads_2010
>
>
>
> ________________________________
> From: Taxacom <taxacom-bounces at mailman.nhm.ku.edu> on behalf of Kenneth
> Kinman <kinman at hotmail.com>
> Sent: Tuesday, June 12, 2018 7:10 PM
> To: Michael Heads
> Cc: Taxacom
> Subject: Re: [Taxacom] Oceanic dispersal vs. vicariance
>
> Hi Michael,
>
> I cannot imagine transoceanic dispersal on an actual floating
> island with cliffs. However, a huge floating raft composed of many
> hundreds of trees and soil clinging to the roots of those which were upside
> down seems very possible. So I view some of the anti-vicariance views of
> Alan de Queiroz as being a bit extreme.
>
> On the other hand, I would tend to agree with Goswami and Upchurch,
> 2010, in arguing against Heads, 2010:
>
> "Heads (2010) argued for the use of continental break-up dates as
> calibration points for molecular clocks when the taxon of interest is
> widely distributed but dispersal across open oceans is considered
> improbable. Using this method, he estimated that the placental mammal
> clade Primates originated in the Early Jurassic, requiring a 130 million
> year ghost lineage before the first euprimate fossils appear in the record.
> We demonstrate that this argument is flawed for several reasons."
> I cannot imagine ever finding primate fossils in the Early Jurassic
> (or even the Early Cretaceous). I assume John Grehan would probably argue
> for such early primates, but I just can't imagine such a long ghost lineage
> as being likely. I can see rodents living underground (perhaps hibernating
> for an extended period) surviving the Cretaceous-Paleocene extinction
> event, but not primates.
> Anyway, as I said before, there seem to be some extreme views on
> both sides of the debate over vicariance vs. transoceanic dispersal. And
> the truth is very likely in between, and I reject such extremes on both
> sides of the debate.
> ------------------Ken
> P.S. Here is a weblink to the abstract of Goswami and Upchurch, 2010: <
> https://www.researchgate.net/publication/229977172_The_
> dating_game_A_reply_to_Heads_2010> https://www.researchgate.net/
> publication/229977172_The_dating_game_A_reply_to_Heads_2010
>
>
>
> ________________________________
> From: Michael Heads <m.j.heads at gmail.com>
> Sent: Monday, June 11, 2018 5:43 PM
> To: Kenneth Kinman
> Cc: Taxacom
> Subject: Re: [Taxacom] Oceanic dispersal vs. vicariance
>
> Ken,
>
> There has been no long-standing debate between Alan de Queiroz and myself.
> I helped him out a lot with his book, providing long replies to his many
> questions about the modern history of the subject in a whole series of
> emails. I knew he disagreed with my views, but I was happy to help out,
> even though I was very busy in Mexico at the time. I was surprised when the
> book came out. I was the subject of the chapter 'Over the edge of reason'
> and portrayed as barking mad. (My guess he was looking for a job and trying
> to impress the right people). I wrote one article reviewing the book.
>
> I don't have his book with me, but somewhere in it there is a whole page
> plate of a painting showing a literal floating island - not just a mass of
> vegetation, but a real island, with cliffs, different types of forest etc.
> The island is moving in a straight line across the sea and leaving a wake
> in its trail. How does that work?!
>
> Which cases of trans-oceanic vicariance do you agree with?
>
> On Mon, Jun 11, 2018 at 2:25 PM, Kenneth Kinman <kinman at hotmail.com
> <mailto:kinman at hotmail.com>> wrote:
> Hi all,
>
> I've been reading a variety of papers on the debate (beginning
> about 2005) between Alan de Queiroz (and others) on the one hand and
> Michael Heads (and others, incl. John Grehan) on the other. I have come to
> the conclusion that both sides represent polar opposites in the debate
> between oceanic dispersal and vicariance. The truth is probably somewhere
> in between, meaning that both sides are right about some cases, but wrong
> in others. Not at all surprising.
>
> Perhaps the strongest case for a large number of oceanic dispersals
> is probably from the African mainland to Madagascar. And the case for
> numerous oceanic dispersals between the African mainland and South America
> (when they were closer together) is more controversial, but there is
> apparently evidence that some of those dispersals were along island chains
> that no longer exist. Whether such islands existed or not, the debate
> between the two sides seems to be largely centered on molecular estimates
> of divergence (about which Grehan seems to repeatedly complain ad
> nauseum). Therefore, my increasing reluctance to respond to his continued
> "baiting". If he wants evidence, there is lots of evidence in the
> literature from many authors (many who seem to be somewhat more objective
> than Alan de Queiroz).
>
> The case for oceanic dispersal from Australia (including Tasmania)
> to New Zealand is admittedly even more controversial. That controversy not
> only involves molecular estimates of divergence, but also whether or not
> New Zealand was completely submerged at some time in the mid Cenozoic.
> Therefore, I am playing devil's advocate in suggesting how one or two
> species of Nothofagus could have rafted from Tasmania to New Zealand in the
> middle of the Cenozoic. Maybe they did and maybe they didn't, but both
> possibilities should be kept in mind. Given the long-standing debate
> between Alan de Queiroz and Michael Heads, I find the Nothofagus case the
> most challenging (even though some earlier Nothofagus dispersals seem
> likely to have been due to vicariance over land in Gondwana). Nothofagus
> distribution could be due to a combination of both vicariance and some
> cases of more recent oceanic dispersal.
>
> ------------------Ken
>
>
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